In many types of electronic apparatus, such as audio apparatus and audio visual apparatus, the apparatus is provided with rotary controls, which may be accommodated in a relatively small area. For apparatus such as music mixing desks there can be in excess of a thousand rotary controls accommodated in a very small area. In known music mixing desks, bar graphs, either horizontally or vertically arranged, are associated with rotary controls to display information on various parameters, the display changing upon the position of the controls. These bar graphs display the information adequately but their horizontal or vertical extent imposes limitations on the density of controls which may be incorporated into the mixing desk and therefore, for a given capacity increases the size of the desk. As these desks are usually controlled by a single person this is in an important consideration.
Relatively recently, rotary controls have been developed in which the rotary control itself, consisting of a single knob or body, incorporates light transmitting elements or light emitting elements, which elements display information relating to a parameter controlled by the knob or body, dependent on the position of the rotary control. In this way, the rotary control itself includes the information display, and separate horizontally or vertically arranged bar graphs are not required. This type of rotary control frees up some space on the apparatus, which space may then be used to incorporate further rotary controls, or other components. However, in apparatus such as music mixing desks where there are a large number of rotary controls, even the incorporation of rotary controls which have integral parameter information displays can be unwieldy. Each rotary control which adjusts a specific parameter needs to be memorised by an operator, and complementary controls, which may adjust linked or cooperating parameters may be spaced apart, which can lead to errors in control of those parameters even if every control is memorised by the operator.
It would therefore be advantageous if rotary controls could be manufactured, such that multiple parameters can be controlled by a single rotary control, whilst still retaining the visual display information corresponding to each parameter.
It would also be advantageous if controls could be manufactured in which multiple parameters could be controlled by a single touch-sensitive control, whilst still retaining the visual display information corresponding to each parameter.
It is therefore an aim of preferred embodiments of the invention to overcome or mitigate at least one problem of the prior art whether disclosed herein or not.